<s>
Junctional	B-Algorithm
rhythm	I-Algorithm
describes	O
an	O
abnormal	O
heart	B-Algorithm
rhythm	I-Algorithm
resulting	O
from	O
impulses	O
coming	O
from	O
a	O
locus	O
of	O
tissue	O
in	O
the	O
area	O
of	O
the	O
atrioventricular	O
node(AV node )	O
,	O
the	O
"	O
junction	O
"	O
between	O
atria	O
and	O
ventricles	O
.	O
</s>
<s>
Current	O
then	O
passes	O
from	O
the	O
atria	O
through	O
the	O
atrioventricular	O
node	O
and	O
into	O
the	O
bundle	B-Algorithm
of	I-Algorithm
His	I-Algorithm
,	O
from	O
which	O
it	O
travels	O
along	O
Purkinje	B-Algorithm
fibers	I-Algorithm
to	O
reach	O
and	O
depolarize	O
the	O
ventricles	O
.	O
</s>
<s>
In	O
junctional	B-Algorithm
rhythm	I-Algorithm
,	O
however	O
,	O
the	O
sinoatrial	O
node	O
does	O
not	O
control	O
the	O
heart	O
's	O
rhythm	O
–	O
this	O
can	O
happen	O
in	O
the	O
case	O
of	O
a	O
block	O
in	O
conduction	B-Algorithm
somewhere	O
along	O
the	O
pathway	O
described	O
above	O
,	O
or	O
in	O
sick	B-Algorithm
sinus	I-Algorithm
syndrome	I-Algorithm
,	O
or	O
many	O
other	O
situations	O
.	O
</s>
<s>
When	O
this	O
happens	O
,	O
the	O
heart	O
's	O
atrioventricular	O
node	O
or	O
bundle	B-Algorithm
of	I-Algorithm
His	I-Algorithm
can	O
take	O
over	O
as	O
the	O
pacemaker	O
,	O
starting	O
the	O
electrical	O
signal	O
that	O
causes	O
the	O
heart	O
to	O
beat	O
.	O
</s>
<s>
Depending	O
on	O
where	O
the	O
rhythm	O
originates	O
in	O
the	O
AV	O
node	O
,	O
the	O
atria	O
can	O
contract	O
before	O
ventricular	O
contraction	O
due	O
to	O
retrograde	O
conduction	B-Algorithm
,	O
during	O
ventricular	O
contraction	O
,	O
or	O
after	O
ventricular	O
contraction	O
.	O
</s>
<s>
Junctional	B-Algorithm
rhythm	I-Algorithm
can	O
be	O
diagnosed	O
by	O
looking	O
at	O
an	O
ECG	B-Application
:	O
it	O
usually	O
presents	O
without	O
a	O
P	O
wave	O
or	O
with	O
an	O
inverted	O
P	O
wave	O
.	O
</s>
<s>
Junctional	B-Algorithm
rhythm	I-Algorithm
is	O
seen	O
equally	O
in	O
men	O
and	O
women	O
,	O
and	O
can	O
be	O
seen	O
intermittently	O
in	O
young	O
children	O
and	O
athletes	O
,	O
especially	O
during	O
sleep	O
.	O
</s>
<s>
It	O
occurs	O
commonly	O
in	O
patients	O
with	O
sinus	B-Algorithm
node	I-Algorithm
dysfunction	I-Algorithm
.	O
</s>
<s>
1/600	O
cardiology	O
patients	O
over	O
the	O
age	O
of	O
65	O
have	O
sinus	B-Algorithm
node	I-Algorithm
dysfunction	I-Algorithm
.	O
</s>
<s>
Anything	O
that	O
impairs	O
the	O
SA	O
node	O
can	O
potentially	O
lead	O
to	O
a	O
junctional	B-Algorithm
rhythm	I-Algorithm
.	O
</s>
<s>
The	O
presentation	O
and	O
symptoms	O
a	O
patient	O
can	O
present	O
with	O
are	O
varied	O
and	O
often	O
dependent	O
on	O
the	O
underlying	O
cause	O
of	O
the	O
junctional	B-Algorithm
rhythm	I-Algorithm
.	O
</s>
<s>
Other	O
nonspecific	O
findings	O
include	O
dizziness	O
,	O
fatigue	O
,	O
palpitations	B-Algorithm
,	O
and	O
passing	O
out	O
.	O
</s>
<s>
This	O
diagnosis	O
is	O
made	O
via	O
ECG	B-Application
.	O
</s>
<s>
The	O
first	O
finding	O
is	O
that	O
junctional	B-Algorithm
rhythms	I-Algorithm
are	O
regular	O
rhythms	O
.	O
</s>
<s>
Since	O
the	O
impulse	O
still	O
travels	O
down	O
the	O
bundle	B-Algorithm
of	I-Algorithm
His	I-Algorithm
,	O
the	O
QRS	O
will	O
not	O
be	O
wide	O
.	O
</s>
<s>
Junctional	B-Algorithm
rhythms	I-Algorithm
can	O
present	O
with	O
either	O
bradycardia	B-Algorithm
,	O
a	O
normal	O
heart	O
rate	O
,	O
or	O
tachycardia	B-Application
.	O
</s>
<s>
Junctional	O
bradycardia	B-Algorithm
is	O
a	O
rhythm	O
that	O
still	O
originates	O
in	O
the	O
AV	O
node	O
or	O
bundle	B-Algorithm
of	I-Algorithm
His	I-Algorithm
,	O
but	O
simply	O
beats	O
at	O
a	O
rate	O
less	O
than	O
40	O
beats	O
per	O
minute	O
.	O
</s>
<s>
Junctional	B-Algorithm
escape	I-Algorithm
rhythm	O
is	O
a	O
rhythm	O
that	O
still	O
originates	O
in	O
the	O
AV	O
node	O
or	O
bundle	B-Algorithm
of	I-Algorithm
His	I-Algorithm
,	O
but	O
beats	O
at	O
the	O
intrinsic	O
automaticity	O
of	O
the	O
AV	O
node	O
,	O
between	O
40	O
and	O
60	O
beats	O
per	O
minute	O
.	O
</s>
<s>
Accelerated	B-Algorithm
junctional	I-Algorithm
rhythm	I-Algorithm
is	O
when	O
the	O
rhythm	O
of	O
emerged	O
impulses	O
is	O
more	O
than	O
40	O
to	O
60	O
beats	O
per	O
minute	O
,	O
which	O
is	O
the	O
natural	O
range	O
of	O
the	O
junction	O
.	O
</s>
<s>
Junctional	B-Algorithm
tachycardia	I-Algorithm
is	O
a	O
rhythm	O
that	O
still	O
originates	O
in	O
the	O
AV	O
node	O
or	O
bundle	B-Algorithm
of	I-Algorithm
His	I-Algorithm
,	O
but	O
simply	O
beats	O
at	O
a	O
rate	O
above	O
100	O
beats	O
per	O
minute	O
.	O
</s>
